Overloading operator for a class in another template class

Question

How should I define my friend operator outside if I'm overloading a comparison operator for a class that is in a template class? Sorry, I probably declared the friend function wrong too. I'm just that bad with templates.

Like:

template<typename T>
class Graph 
{
    class Edge; 
    map<T, set<Edge>>edges;

    ...
};

template<typename T>
class Graph<T>::Edge
{
    ...

    friend bool operator==(Edge e1, Edge e2); // How should I declare/define this operator???

    ...
};